CAS 9003-31-0: Polyisobutylene ((C4H8)n)
Identity
| CAS Number | 9003-31-0 |
| Molecular Formula | (C4H8)n |
| IUPAC Name | poly(2-methylpropene) |
| Molecular Weight | 56.11 g/mol |
| SMILES | C=C(C)C |
| Synonyms | PIB, polyisobutene, butyl rubber base, polyisobutylene |
2D Structure
Physical Properties
| Density | 0.92 g/mL at 25°C |
| Boiling Point | None°C |
| Melting Point | 44.0°C |
| Flash Point | 200.0°C |
| Vapor Pressure | 0.0 kPa at 20°C |
| Refractive Index | nD = 1.509 |
| Dielectric Constant | ε = 2.3 |
Safety & GHS Classification
Storage: Store in cool, dry place. Very stable polymer. Low permeability to gases. Molecular weights range from 300 to millions.
Material Compatibility Matrix
Plastics
| Material | Rating |
|---|---|
| PTFE | Excellent |
| PVC | Good |
| PE | Good |
| PP | Good |
| PEEK | Excellent |
| PVDF | Good |
Rubbers
| Material | Rating |
|---|---|
| Viton | Fair |
| NBR | Good |
| EPDM | Good |
| Silicone | Good |
| FKM | Fair |
Metals
| Material | Rating |
|---|---|
| Stainless 316 | Excellent |
| Aluminum | Excellent |
| Copper | Excellent |
| Brass | Excellent |
Applications
- Inner liner of tubeless tires (butyl rubber)
- Fuel and lubricant additive (viscosity modifier)
- Chewing gum base
- Adhesive manufacturing
- Electrical insulation
- Caulking and sealant
- Damping material (vibration isolation)
- Pipe wrapping
External References: PubChem